Exterior joint part comprising a supporting disc

ABSTRACT

An outer joint part ( 12 ) of a constant velocity universal joint ( 11 ) in the form of a joint bell ( 16 ) with an attached connecting journal ( 17 ) and a radial supporting face ( 18 ) at the joint bell ( 16 ). The outer joint part ( 12 ), by threading, can be tensioned relative to a wheel hub ( 25 ) slid on to the connecting journal and which is supported either directly or indirectly on the supporting face ( 18 ). An annular disc ( 22 ) which is made of a low-friction material and is positioned on the supporting face ( 18 ) so as to be concentric relative to the connecting journal ( 17 ).

BACKGROUND

The invention relates to an outer joint part of a constant velocityuniversal joint in the form of a joint bell with an attached connectingjournal and a radial supporting face at the joint bell at the base ofthe connecting journal, wherein the outer joint part, by means ofthreading means, can be clamped to a wheel hub which has to be slid onto the connecting journal and which is supported either directly orindirectly on the supporting face.

Furthermore, the invention relates to an assembly consisting of aconstant velocity universal joint with an outer joint part in the formof a joint bell with an attached connecting journal and a radialsupporting face at the joint bell at the base of the connecting journal,as well as of a wheel hub which is slid on to the connecting journal andwhich, via threading means, is clamped to the outer joint part, whereinthe wheel hub is directly or indirectly supported on the supportingface.

Assemblies of this type are used in the region of wheel bearings ofdriven motor vehicle wheels. The constant velocity universal joint formsthe joint at the wheel end of driveshafts or sideshafts of motorvehicles. When mounting the shafts to the hub assembly, there takesplace an axial clamping operation between the wheel hub and the outerjoint part via threading means, wherein mutual support is effectedeither via the inner bearing races of a wheel bearing attached to thewheel hub or via the wheel hub itself, in each case relative to asupporting face at the outer joint part. When the vehicle is in use, inspite of high clamping forces, the occurrence of micro movements at thesupporting face of the outer joint part is possible which generate agreat deal of noise. Said micro movements are the result of anon-uniform introduction of force and possibly also of rotating bendingmoments. Even if the surfaces contacting one another are very carefullymachined, it has so far not been possible to avoid said noisedevelopment.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to solve said problemby suppressing the development of noise. The solution provides an outerjoint part of said type which is characterized by an annular disc whichis made of a low-friction material and which is positioned on thesupporting face so as to be concentric relative to the connectingjournal. More particularly, the annular disc can comprise a cylindricalportion which starts from the outer edge of same and is positioned on asuitable cylindrical portion at the joint bell in a force-locking way,i.e. under a radial pretension.

Accordingly an assembly a constant velocity universal joint and a wheelhub of said type is thus characterized in that there is provided anannular disc which is made of a low-friction material, which ispositioned directly on the supporting face so as to be concentricrelative to the connecting journal and which accommodates the clampingforces of the threads. According to a first embodiment, on to the wheelhub there are slipped bearings which are axially pretensioned by threadsand whose inner bearing races are axially supported on the wheel hub onthe one hand and on the annular disc on the other hand under the load ofthe threads. Alternatively, bearings are slipped on to the wheel hub,with the inner bearing races of said bearings being clamped to the wheelhub by an annular bead at the wheel hub, with the annular bead beingdirectly supported on the annular disc under the load of the threadingmechanism. The annular bead is produced by plastically deforming thewheel hub after the bearings have been slipped on. The low-frictionannular disc is selected in such a way that the micro movements whichare now divided up between the annular disc and the outer joint part onthe one hand and the annular disc and the inner bearing race or beadingon the other hand can no longer lead to any noise.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are illustrated in the drawingswhich will be described below and wherein

FIG. 1 is a longitudinal section through a constant velocity universaljoint having an inventive outer joint part with a supporting disc.

FIG. 2 is a longitudinal section through a first embodiment of aninventive assembly of a constant velocity universal joint and a wheelhub.

FIG. 3 is a longitudinal section through a second embodiment of aninventive assembly of a constant velocity universal joint and a wheelhub.

FIG. 4 is a longitudinal section through a modified embodiment of aninventive assembly similar to that shown in FIG. 2.

FIG. 5 is a longitudinal section through a modified embodiment of aninventive assembly similar to that shown in FIG. 3.

FIG. 6 is a detailed illustration of an annular disc in accordance withthe present invention, the annular disc illustrated as a non-ferrousmetal.

FIG. 7 is a detailed illustration of an annular disc in accordance withthe present invention, the annular disc illustrated as an anti-frictioncoating.

FIG. 8 is a detailed illustration of an annular disc in accordance withthe present invention, the annular disc illustrated as a plasticmaterial.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a constant velocity universal joint 11 which comprises aninventive outer joint part 12, an inner joint part 13, a cage 14 as wellas one of a plurality of torque transmitting balls 15. The inventiveouter joint part 12 comprises a joint bell 16, a connecting journal 17attached thereto as well as a radial supporting face 18 arrangedconcentrically relative to said connecting journal 17. On the outside ofthe connecting journal 17 there is provided shaft teeth 19 (splines) toprovide a torque transmitting engagement with a wheel hub 25 (FIG. 2) aswell as an inner bore 20 with an inner thread 21 for threading in atensioning screw. On to the radial supporting face 18, there is placed asupporting disc 22 which, at its outer circumference, changes into acylindrical portion 23 which is held in a form-fitting and positive wayon a cylindrical step 24 of the outer joint part 12.

In FIG. 2, any details identical to those shown in FIG. 1 have beengiven the same reference numbers. A wheel hub 25 which, by of counterteeth 26 (splines), form-fittingly and positively engages the shaftteeth 19 has been slipped on to the connecting journal 17. The wheel hub25 is followed by a wheel flange 27 which is connected to a brake disc28 in a way not shown in greater detail. Via a tensioning bolt 29 whosebolt head 30 is supported on the wheel flange 27 and which is threadedinto the inner thread 21 of the through-aperture 20, the wheel hub 25 isclamped to the outer joint part 12. On to the wheel hub 25, there isslipped a double-row wheel bearing 34 whose inner bearing races 32, 33are axially supported on the one hand on a supporting face or step 35 ofthe wheel flange 27 and, on the other hand, on the supporting disc 22under the pretensioning force of the bolt 29. The outer bearing race 31of the wheel bearing 34 has been inserted into a wheel carrier 36. Inthe type of wheel bearing selected, the pretension of the bearing is setby the tensioning bolt 29.

In FIG. 3, any details identical to those shown in FIG. 1 have beengiven the same reference numbers. A wheel hub 125 which, by innersplines 26, form-fittingly and positively engages the shaft splines 19has been slipped on to the connecting journal 17. The wheel hub 125 isfollowed by a wheel flange 27 which is connected to a brake disc 28 in away not shown in greater detail. Via a tensioning bolt 29 whose bolthead 30 is supported on the wheel flange 27 and which is threaded intothe inner thread 21 of the through-aperture 20, the wheel hub is clampedto the outer joint part 12. On to the wheel hub 17 there is slipped awheel bearing 34 whose inner bearing races 32, 33 are supported on asupporting face or step 35 of the wheel flange 27 and axially tensionedand fixed by a beading 39 of the wheel hub 125. By an annular face, saidbeading 39 rests against the annular disc 22 under the pretensioningforce of the bolt 29. In this case, too, the outer bearing race 31 ofthe wheel bearing 34 is inserted into a wheel carrier 36. The pretensionof the bearing is determined by the production steps and the shape ofthe beading 39.

In FIG. 4, any details which are identical to those shown in FIG. 2 havebeen given the same reference numbers. To that extent, reference is madeto the description of FIG. 2. The parts illustrated which have slightlydifferent geometries are indexed by multiples of 100. The bolt head 130of the bolt 129, for example, clearly deviates from that of the previousfigures. The brake disc is not shown. The wheel bearing 134 is shown inits entirety, including seals and bearing cages. The outer bearing race131 is integral with the wheel carrier 136. The wheel flange 127 and thewheel carrier 136 are shown to have flange holes 37, 38. The supportingdisc 22 prevents direct contact between the inner bearing race 133 andthe supporting face 118 of the outer joint part 112, so that, underload, relative micro movements are accommodated by the supporting discin a noise-free way.

In FIG. 5, any details which are identical to those shown in FIG. 4 havebeen given the same reference numbers. To that extent, reference is madeto the description of FIGS. 2 and 4. Again, the parts illustrated whichhave slightly different geometries, such as the bolt head 130 of thebolt 129, are indexed by multiples of 100. The brake disc is not shown.The wheel bearing 134 is shown in its entirety, including seals andbearing cages. The outer bearing race is integral with the wheel carrier136. The wheel flange 227 and the wheel carrier 136 are shown to haveflange holes 37, 38. The supporting disc 22 prevents direct contactbetween the beading 139 and the supporting face 118 of the outer jointpart 112, so that, under load, relative micro movements are accommodatedby the supporting disc in a noise free way.

According to one embodiment, the annular disc 22 is an iron material andcomprises a coating of Molykote D321 R or equivalent anti frictionlubricant coating 777. Before the coating is applied, the annular disccan be phosphated or sandblasted. In a further aspect, the annular discis bronze or non-ferrous metal 22′. Finally, according to a furtherembodiment it is possible for the annular disc to be any suitable,high-resistance, optionally fiber-reinforced plastic 22″.

1. A constant velocity universal joint assembly comprising: a constantvelocity universal joint with an outer joint part in the form of a jointbell with an attached connecting journal and a radial supporting face atthe joint bell at the base of the connecting journal; a wheel hub whichis slid on to the connecting journal and which, via threading, isclamped to the outer joint part, wherein the wheel hub is directly orindirectly supported on the supporting face; an annular disc made of alow-friction material, which is positioned directly on the supportingface so as to be concentric relative to the connecting journal and whichaccommodates the clamping forces of the threading; and bearingspositioned on the wheel hub, wherein an inner bearing race of saidbearings is directly axially supported on the annular disc.
 2. Aconstant velocity universal joint assembly according to claim 1, whereinthe annular disc comprises a cylindrical portion which starts from anouter edge of the annular disc and is positioned on the joint bell in aforce-locking way.
 3. A constant velocity universal joint assemblyaccording to claim 1, wherein the annular disc comprises ananti-friction coating.
 4. A constant velocity universal joint assemblyaccording to claim 1, wherein the annular disc comprises bronze ornon-ferrous metal.
 5. A constant velocity universal joint assemblyaccording to claim 4, wherein the annular disc comprises bronze.
 6. Aconstant velocity universal joint assembly according to claim 1, whereinthe annular disc comprises plastics.
 7. A constant velocity universaljoint assembly comprising: a constant velocity universal joint with anouter joint part in the form of a joint bell with an attached connectingjournal and a radial supporting face at the joint bell at the base ofthe connecting journal; a wheel hub which is slid on to the connectingjournal and which, via threading, is clamped to the outer joint part,wherein the wheel hub is directly or indirectly supported on thesupporting face; an annular disc made of a low-friction material, whichis positioned directly on the supporting face so as to be concentricrelative to the connecting journal and which accommodates the clampingforces of the threading; and bearings positioned on the wheel hub andwhose inner bearing races are axially clamped to the wheel hub byannular beading at the wheel hub, wherein the annular beading isdirectly axially supported at the annular disc.
 8. A constant velocityuniversal joint assembly according to claim 7, wherein the annular disccomprises a cylindrical portion which starts from an outer edge of theannular disc and is positioned on the joint bell in a force-locking way.9. A constant velocity universal joint assembly according to claim 7,wherein the annular disc comprises an anti-friction coating.
 10. Aconstant velocity universal joint assembly according to claim 7, whereinthe annular disc comprises bronze or non-ferrous metal.
 11. A constantvelocity universal joint assembly according to claim 10, wherein theannular disc comprises bronze.
 12. A constant velocity universal jointassembly according to claim 7, wherein the annular disc comprisesplastics.